Calculate cash flow from investing activities.

$\backslash$table$[[,$Year $1,$Year $2],[$Interest paid to debtholders,$72\mathrm{.}0,77\mathrm{.}0],[$Buyback of company's own shares,$67\mathrm{.}0,89\mathrm{.}0],[$Non current investments balance,$82\mathrm{.}0,90\mathrm{.}0],[$Net PP&E$,564\mathrm{.}0,568\mathrm{.}0],[$Depreciation$,80\mathrm{.}0,85\mathrm{.}0]]$